Toys N Bricks is reporting that both Wal-Mart and Target are conducting in-store clearances on select LEGO sets of 30% to 50% off original prices. One particular collection to be on the watch for are the LEGO Prince of Persia sets.
Prince of Persia (PoP) was well received by the AFOL community, but due to a lackluster box office in the US (although I heard it did quite well overseas) we may see some deep discounts leading up to the holidays.
Sets like 7569, Desert Attack, and 7570, Ostrich Race, had some great minifig parts, weapons, and animals ready for customization. These sets were already affordable, but with these additional discounts, there may be real 'army building potential' here.
You may want to call your local store to see if they still have items in stock and how low the discounts are in your area before venturing out.
You can also see the other sets being discounted by clicking through the link below.
(UPDATE 8/20: I personally went to my local Target and Wal-Mart last night, but didn't see any LEGO PoP on clearance. There were several LEGO Star Wars items on sale at Target, however. My Wal-Mart appeared to be re-setting their planograms and there were LEGO items on clearance. You'll have to hunt them out - the items I found were in the Lawn & Garden area!)
(Via Toys N Bricks)